<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>09-交互两个变量</title>
</head>

<body>
  <script>
    let num1 = 10
    let temp 
    let num2 = 20
    temp = num1
    num1 = num2
    num2 = temp
    console.log(num1,temp,num2);
  </script>
</body>
</html>